U.S. patent application number 14/964981 was filed with the patent office on 2016-06-23 for battery monitoring apparatus.
This patent application is currently assigned to DENSO CORPORATION. The applicant listed for this patent is DENSO CORPORATION. Invention is credited to Shinsuke KAWAZU, Masamitsu SHINBO.
Application Number | 20160178700 14/964981 |
Document ID | / |
Family ID | 56099819 |
Filed Date | 2016-06-23 |
United States Patent
Application |
20160178700 |
Kind Code |
A1 |
KAWAZU; Shinsuke ; et
al. |
June 23, 2016 |
BATTERY MONITORING APPARATUS
Abstract
A battery monitoring apparatus is for a vehicle including a
battery and a starter for starting an engine thereof by using
electric power supplied from the battery. The battery monitoring
apparatus includes a current obtaining section that obtains, as a
discharge current value, a value of a discharge current flowing out
from the battery while the engine is being started, a current
determination section that determines whether or not the discharge
current value is smaller than a predetermined threshold value, a
start determination section that determines whether or not the
engine has been started up, and a jump-start determination section
that determines that the engine has been jump-started if the
discharge current value is determined to be smaller than the
threshold value and the engine is determined to have been started
up.
Inventors: |
KAWAZU; Shinsuke;
(Kariya-shi, JP) ; SHINBO; Masamitsu; (Iwata-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENSO CORPORATION |
Kariya-city |
|
JP |
|
|
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
56099819 |
Appl. No.: |
14/964981 |
Filed: |
December 10, 2015 |
Current U.S.
Class: |
73/114.61 |
Current CPC
Class: |
F02N 11/0862 20130101;
F02N 2200/102 20130101; F02N 2200/0814 20130101; G01R 31/382
20190101; F02N 11/087 20130101; H02J 1/122 20200101; G01R 31/3647
20190101; F02N 2200/101 20130101; F02N 2200/062 20130101; F02N
2200/0801 20130101; F02N 11/0825 20130101; H02J 7/1461 20130101;
F02N 11/12 20130101; F02N 11/0848 20130101; F02N 11/10
20130101 |
International
Class: |
G01R 31/36 20060101
G01R031/36; F02N 11/08 20060101 F02N011/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 2014 |
JP |
2014-255033 |
Claims
1. A battery monitoring apparatus for a vehicle including a battery
and a starter for starting an engine thereof by using electric
power supplied from the battery, comprising: a current obtaining
section that obtains, as a discharge current value, a value of a
discharge current flowing out from the battery while the engine is
being started; a current determination section that determines
whether or not the discharge current value is smaller than a
predetermined threshold value; a start determination section that
determines whether or not the engine has been started up; and a
jump-start determination section that determines that the engine
has been jump-started if the discharge current value is determined
to be smaller than the threshold value and the engine is determined
to have been started up.
2. The battery monitoring apparatus according to claim 1, wherein,
when positive side and negative side terminals of the battery are
connected with positive side and negative side booster cables,
respectively, the current obtaining section obtains, as the
discharge current value, a value of a current flowing between the
positive terminal and the positive side booster cable, or a value
of a current flowing between the negative terminal and the negative
side booster cable.
3. The battery monitoring apparatus according to claim 2, further
comprising a first wire connected to the positive terminal, a
second wire connected to the negative terminal, and a current
detection section that detects one of a current flowing through the
first wire and a current flowing through the second wire, wherein
the current obtaining section obtains, as the discharge current
value, a value of a current flowing through the current detection
section in a state of being connected between one of the positive
and negative terminals and one of the positive side and negative
side booster cables.
4. The battery monitoring apparatus according to claim 1, wherein
the current determination section determines whether or not the
discharge current value is smaller than the threshold value at a
time after an elapse of a predetermined time since start of supply
of electric power to the starter and before the engine reaches a
complete combustion state.
5. The battery monitoring apparatus according to claim 1, wherein
the current determination section determines whether or not the
discharge current value is smaller than the threshold value at a
time when the engine has reached a complete combustion state.
6. The battery monitoring apparatus according to claim 1, further
comprising a data acquiring section that acquires data regarding a
factor affecting the discharge current value, and a threshold
setting section that sets the threshold value in accordance with
the data regarding the factor acquired by the data acquiring
section.
Description
[0001] This application claims priority to Japanese Patent
Application No. 2014-255033 filed on Dec. 17, 2014, the entire
contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a battery monitoring
apparatus for monitoring a battery during start of an engine.
[0004] 2. Description of Related Art
[0005] Since a vehicle battery deteriorates after long-term use, a
jump-start of the engine of an own vehicle may need to be performed
using electric power supplied from a rescue vehicle or the like
when necessary.
[0006] There is known a technique in which a jump-start
determination is made based on the voltage of the battery of an own
vehicle to determine whether the engine of the own vehicle has been
started normally using electric power of the battery of the own
vehicle, or has been jump-started (that is, has been started using
electric power supplied from a rescue vehicle).
[0007] Japanese Patent Application Laid-open No. 2001-107768
describes that an engine is determined to have been jump-started if
the voltage of the battery of an own vehicle was higher than a
predetermined threshold value immediately before starting the
engine. The threshold value is set between the voltage of the
battery when the engine is started normally, and the voltage of the
battery when the engine is jump-started by being supplied with
electric power from an alternator of a rescue vehicle.
[0008] However, the above described conventional technique has the
problem as described in the following. In this conventional
technique, if the engine of the rescue vehicle is stopped and
accordingly the alternator of the rescue vehicle is out of
operation, or if the alternator of the rescue vehicle is inhibited
from generating electric power, there is a concern that the engine
of the own vehicle may be determined to have not been jump-started,
although it has been jump-started actually.
[0009] In vehicles provided with idling stop functionality,
automatically stop of an engine is inhibited after the engine has
been jump-started. Accordingly, if the jump-start determination is
not made correctly, the idling stop function may be adversely
affected.
SUMMARY
[0010] An exemplary embodiment provides a battery monitoring
apparatus for a vehicle including a battery and a starter for
starting an engine thereof by using electric power supplied from
the battery, including:
[0011] a current obtaining section that obtains, as a discharge
current value, a value of a discharge current flowing out from the
battery while the engine is being started;
[0012] a current determination section that determines whether or
not the discharge current value is smaller than a predetermined
threshold value;
[0013] a start determination section that determines whether or not
the engine has been started up; and
[0014] a jump-start determination section that determines that the
engine has been jump-started if the discharge current value is
determined to be smaller than the threshold value and the engine is
determined to have been started up.
[0015] According to the exemplary embodiment, there is provided a
battery monitoring apparatus capable of correctly determining
whether or not a vehicle has been jump-started irrespective of the
power generation state of a rescue vehicle or the like.
[0016] Other advantages and features of the invention will become
apparent from the following description including the drawings and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In the accompanying drawings:
[0018] FIG. 1 is a diagram schematically showing the structure of
an engine system of an own vehicle provided with a battery
monitoring apparatus according to an embodiment of the
invention;
[0019] FIG. 2 is a diagram for explaining an example of electrical
connection between the own vehicle and a rescue vehicle at the time
of jump-starting the engine of the own vehicle;
[0020] FIG. 3 is a diagram for explaining another example of
electrical connection between the own vehicle and the rescue
vehicle at the time of jump-starting the engine of the own
vehicle;
[0021] FIG. 4 is a graph showing temporal variations of a battery
current during each of normal start and jump-start of the engine of
the engine system;
[0022] FIG. 5 is a flowchart showing steps of a process for making
a jump-start determination; and
[0023] FIG. 6 is a time chart for explaining an example of an
operation for starting the engine.
PREFERRED EMBODIMENTS OF THE INVENTION
[0024] FIG. 1 is a diagram schematically showing the structure of
an engine system of an own vehicle having an engine 10, the own
vehicle being provided with an idling stop function and a battery
monitoring apparatus according to an embodiment of the
invention.
[0025] As shown in FIG. 1, the engine 10 is provided with a starter
12 for starting the engine 10 by cranking the engine 10.
[0026] The engine 10 is coupled to an alternator 13 through a belt
or the like at its crankshaft. The alternator 13 is connected with
a battery 11 and electrical loads 14 such as an audio device. The
battery 11 is disposed in the engine compartment, and connected
with the electrical loads 14 through an ignition switch 16. The
alternator 13 is driven to rotate by the engine 10 to generate
electric power to be supplied to the battery 11, the electrical
loads 14 and so on.
[0027] The starter 12 is connected to the battery 11 through a
relay 23 and the ignition switch 16. The starter 12 starts to be
driven when the engine 10 is started manually by a vehicle driver's
operation of an ignition key, or when the engine 10 is started
automatically by the idling stop function. In the case of the
manual start of the engine 10 by the vehicle driver, if the
ignition key is set to a start position, the ignition switch 16 is
closed to supply current to the relay 23. As a result, the relay 23
is closed to supply electric power to the starter 12 from the
battery 11. Consequently, the starter 12 is driven to start the
engine 10. In the case of the automatic start of the engine 10 by
the idling stop function, the relay 23 is controlled to be closed
to cause the starter 12 to start the engine 10.
[0028] The electrical loads 14 are supplied with electric power
from the alternator 13 and the battery 11. Specifically, when the
ignition key is set to the ACC position, the ACC switch of the
ignition switch 16 is closed. As a result, the relay 23 disposed
between the battery 11 and the electrical loads 14 is closed to
supply electric power to the electrical loads 14 from the battery
11. While the engine 10 is stopped by the idling stop function, the
relay 23 is controlled to be closed to supply electric power to the
electrical loads 14 from the battery 11.
[0029] The engine control system includes various sensors including
a current sensor 17 for detecting battery current, a vehicle speed
sensor 19 for detecting the vehicle speed, an accelerator sensor 20
for detecting a depression amount of the accelerator pedal, a brake
sensor 21 for detecting a depression amount of the brake pedal and
an engine hood sensor 22 for detecting opening and closing of the
engine hood. These sensors are connected to the ECU 15. The ECU 15
is constituted mainly of a microcomputer which includes a CPU, a
ROM and a RAM, and executes various programs stored in the ROM. The
ECU 13 starts up when the vehicle driver sets the ignition key to
the IG position, and operates on electric power supplied from the
battery 11.
[0030] The ECU 15 sends signals to the engine 10 to drive a fuel
injection device and an ignition device in accordance with
requirements to run the engine 10 and the running state of the
engine 10. The ECU 15 controls power generation amount of the
alternator 13 in accordance with the voltage of the battery 11, and
the SOC (or the remaining capacity) of the battery 11. The SOC of
the battery 11 can be calculated from the battery voltage or the
battery current. The ECU 15 has a later-explained start
determination function for determining whether the engine 10 has
been jump-started or started normally.
[0031] The ECU 15 performs idling stop control in accordance with
the vehicle speed, the depression amount of the accelerator pedal,
the depression amount of the brake pedal, the voltage of the
battery 11 and so on. Incidentally, it is possible that the engine
control and the idling stop function are performed by different
ECUs.
[0032] Next, an example of the jump-start and the jump-start
determination are explained in detail. In this embodiment, it is
determined whether the engine 10 has been jump-started or not based
on a discharge current value Ib detected by the current sensor 17,
the discharge current value Ib being the value of the discharge
current flowing out from the battery 11 of the own vehicle 7 after
the starter 12 starts to be supplied with electric power.
[0033] FIG. 2 is a diagram for explaining an example of electrical
connection between the own vehicle 7 and a rescue vehicle 30 at the
time of jump-starting the engine 10 of the own vehicle 7. In the
example of FIG. 2, the battery 11 of the own vehicle 7 and a
battery 31 of the rescue vehicle 30 are connected to each other
through a pair of booster cables 32. More specifically, the
positive terminal of the battery 11 of the own vehicle 7 is
connected to one end a positive side cable (a first wire) 8, the
other end of the positive side cable 8 being connected with a
connection member X1 which is connected with the starter 12, the
alternator 13 and the electrical loads 14. The negative terminal of
the battery 11 is connected to one end of a negative side cable (a
second wire) 9, the other end of the negative side cable being
connected with the vehicle body or a connection member X2 which is
connected with the vehicle body. The connection member X1 of the
own vehicle 7 and the positive terminal of the battery 31 of the
rescue vehicle 30 are connected to each other through the positive
side booster cable 32. On the other hand, the connection member X2
of the own vehicle 7 and the negative terminal of the battery 31 of
the rescue vehicle 30 are connected to each other through the
negative side booster cable 32. In such a connection state,
electric power is supplied to the starter 12 of the own vehicle 7
from the battery 31 of the rescue vehicle 30 to jump-start the
engine 10 of the own vehicle 7.
[0034] The current sensor 17 is provided in the negative side cable
9 for detecting the value of the battery current flowing through
the battery 11. The value of the battery current detected by the
current sensor 17 is outputted to the ECU 15. In this embodiment,
the discharge current value Ib itself is detected by the current
sensor 17 provided in the negative side cable 9. Connecting the
negative side booster cable 32 to the connection member X2 (the
vehicle body) is prescribed in an operation and maintenance manual
or the like.
[0035] FIG. 3 is a diagram for explaining another example of
electrical connection between the own vehicle 7 and the rescue
vehicle 30 at the time of jump-starting the engine 10 of the own
vehicle 7. In this example, the current sensor 17 is provided in
the positive side cable 8 of the own vehicle 7 to detect the
discharge current value Ib of the battery 11.
[0036] To jump-start the engine 10, electric power is supplied from
the battery 31 of the rescue vehicle 30 to the starter 12 of the
own vehicle 7. At this time, the discharge current flowing out from
the battery 11 of the own vehicle 7 decreases depending on the
amount of electric power supplied from the rescue vehicle 30.
Therefore, the discharge current value Ib when the engine 10 is
jump-started is smaller than when the engine 10 is started
normally. Accordingly, it is possible to make the jump-start
determination based on the output of the current sensor 17.
[0037] FIG. 4 is a graph showing temporal variations of the battery
current during each of the jump-start and the normal start of the
engine 10. Here, it is assumed that the alternator 13 is stopped
before starting the engine 10 and starts to generate electric power
after the engine 10 has been started up.
[0038] As shown in FIG. 4, in each of the jump start and the normal
start, a large current (an inrush current) flows when the starter
12 starts to be supplied with electric power, because no induced
voltage is present in the starter 12 at this moment. Therefore, the
battery current increases sharply and reaches the maximum of the
discharge current value Ib. Thereafter, the battery current
decreases while fluctuating with the increase of the engine speed.
When the engine 10 reaches a certain rotational speed above which
the engine 10 can run by itself, that is, when the engine 10 has
been started up, the battery 11 starts to be charged by the
alternator 13.
[0039] The value of the discharge current of the battery 11 in the
case of jump starting of the engine 10 is smaller than that in the
case of normal starting of the engine 10 until the engine 10 has
been started up. After start of supply of electric power to the
starter 12, the inrush current changes sharply, and fluctuates
greatly during the period of rotating the crankshaft of the engine
10. Accordingly, the timing to detect the discharge current value
Ib is set within a period in which the inrush current is not
present and before the engine 10 is started up.
[0040] In this embodiment, the period in which the inrush current
flows and the period after the engine 10 is detected to have been
started up are regarded as a "mask period", and the battery current
is detected in a period other than the mask period. Here, the value
of the battery current detected at the timing of completion of
start-up of the engine 10 (the complete combustion timing) is set
as the discharge current value Ib of the battery 11. The jump-start
determination is made based on whether or not the discharge current
value Ib is larger than a predetermined threshold value Th. At the
complete combustion timing, the starter 12 is in a no-load state in
which no rotational load to rotate the crankshaft of the engine is
present. In this no-load state, variation of detection of the
discharge current value Ib is small.
[0041] Next, a process for making the jump-start determination is
explained with reference to the flowchart of FIG. 5. This process
is performed repeatedly at regular time intervals by the ECU
15.
[0042] This process begins in step S11 where it is determined
whether or not the engine 10 is going to be started. If the
determination result in step Sll is affirmative, the process
proceeds to step S12, and otherwise the process is terminated.
[0043] In step S12, it is determined whether or not the engine hood
is open. If the determination result in step S12 is affirmative,
the process proceeds to step S13, and otherwise the process is
terminated. Step S12 may be modified to determine whether or not
the door of the own vehicle is open to access the battery 11 if the
battery 11 is disposed in the cabin.
[0044] In step S13, it is determined whether or not it is timing to
obtain the discharge current value Ib. For example, it is
determined whether it is the timing of completion of start-up (the
complete combustion timing). If the determination result in step
S13 is affirmative, the process proceeds to step S14, and otherwise
the process is terminated. In step S14, the battery current
detected by the current sensor 17 is obtained as the discharge
current value Ib.
[0045] In subsequent step S15, it is determined whether or not the
discharge current value Ib is smaller than or equal to the
threshold value Th. If the determination result in step S13 is
affirmative, the process proceeds to step S16, and otherwise the
process is terminated. In step S16, it is determined that the
engine 10 has been jump-started, and inhibits the engine 10 from
being stopped automatically. Incidentally, if it is determined that
the engine 10 has been jump-started, control to promote power
generation of the alternator 13 or control to supply electric power
preferentially to higher-priority loads may be performed in
addition to inhibiting the engine 10 from being stopped
automatically.
[0046] Next, an example of an operation for starting the engine 10
is explained with reference to the time chart of FIG. 6.
[0047] The starter 12 is driven at time t1 by an operation of the
ignition key. The ECU 15 recognizes that the starter 12 starts to
operate at time t2. Subsequently, the battery 11 starts to
discharge. As shown in FIG. 6, the battery current depends on
whether the engine 10 has been started normally or jump-started.
Thereafter, at a moment when the engine speed reaches the complete
combustion speed at time t3, the battery current is detected as the
discharge current value Ib. Subsequently, the jump-start
determination is made based on the discharge current value Ib.
[0048] Incidentally, the way to detect the complete combustion
state is not limited to the one described above. For example, it is
possible to determine that the engine has reached the complete
combustion state upon detecting that the pinion of the starter 12
is being driven to rotate by the ring gear of the crankshaft of the
engine 10, that is, that the pinion is in a no-load state. More
specifically, it is possible to determine that the engine has
reached the complete combustion state upon detecting that the
torque which the pinion of the starter 12 applies to the ring gear
becomes smaller than a predetermined value, or when the change rate
of the torque is larger than a predetermined value.
[0049] Thereafter, the operation of the ignition key is ended at
time t4, and the ECU 15 recognizes that the engine 10 has been
started up at time t5. Incidentally, in the example of FIG. 6, each
of the period starting from time t2 and continuing for a certain
time and the period after time t3 is a mask period. If the
operation of the ignition key is ended before detecting the
complete combustion state of the engine 10, the period after the
end of the operation is set as the mask period.
[0050] The above described embodiment of the invention provides the
following advantages.
[0051] Since the discharge current value Ib which is the value of
the discharge current flowing out from the battery 11 of the own
vehicle 7 is obtained, it is possible to perform the jump-start
determination correctly irrespective of the power generation state
of the rescue vehicle 30. Further, since a determination whether
engine starting is completed can be made even when the discharge
current value Ib of the battery 11 of the own vehicle 7 is small,
it is possible to correctly determine that the jump-start has been
made.
[0052] The jump-start determination is made based on the discharge
current value Ib obtained when the speed of the engine 10 has
reached the complete combustion determination speed. Accordingly,
since variation of the discharge current value Ib is small, the
jump-start determination can be made with a high degree of
accuracy.
[0053] The discharge current value Ib can be obtained in a period
other than the period immediately after start of supply of electric
power to the starter 12 in which a large current flows.
Accordingly, it is possible to make a comparison correctly between
the discharge current value Ib and the threshold without
excessively increasing the detectable range of the current sensor
17.
[0054] In the above embodiment, it is determined that the engine 10
has been jump-started if the engine 10 has been started up with the
engine hood of the own vehicle 7 being open, and the discharge
current value Ib is detected to be smaller than the threshold value
Th. Accordingly, it is possible to set the threshold value Th to
the safety side (the side at which the engine 10 is apt to be
determined to have been jump-started) in terms of ensuring
robustness.
Other Embodiments
[0055] The above described embodiment may be modified as described
below.
[0056] The ECU 15 may be configured to variably set the threshold
value Th. For example, the ECU 15 may be configured to obtain the
driven state of the electrical loads 14 as a factor affecting the
discharge current value Ib, and set the threshold value Th in
accordance with the driven state of the electrical loads 14. In
this case, the threshold value Th is set higher when power consumed
by the electrical loads 14 is larger and accordingly the discharge
current value Ib is larger. Further, the threshold value Th may be
set variably in accordance with not only the driven state of the
electrical loads 14, but also the outdoor temperature or the
traveling distance of the own vehicle, which affects the discharge
current value Ib.
[0057] Variably setting the threshold value Th as described above
makes it possible to make the jump-start determination correctly
even when the driven state of the electrical loads 14 fluctuates,
causing the discharge state of the battery 11 to fluctuate.
[0058] The threshold value Th may be set depending on the number of
times that the starter 12 is driven. In this case, the threshold
value Th is set smaller when the the number of times that the
starter 12 is driven is greater and accordingly the starter 12 is
assumed to be more deteriorated.
[0059] The threshold value Th may be set depending on the number of
times that the ignition key is operated. When the number of times
that the ignition key is operated is greater, that is, when the
number of times that engine start fails is greater, it can be
assumed that the battery 11 is more deteriorated. Accordingly, when
the number of times that the ignition key is operated is greater,
the threshold value Th is set larger so that the engine 10 is apt
to be determined to have been jump-started.
[0060] In the above embodiment, the jump-start determination is
made based on the discharge current value Ib which is the value of
the discharge current when the engine speed has reached the
complete combustion determination speed. However, the discharge
current value Ib may be the maximum value of the battery current
(the peak value of the inrush current) after start of supply of
electric power to the starter 12, or the value of the battery
current at a moment after an elapse of a predetermined time since
start of supply of electric power to the starter 12, or the average
value of the battery current during a period in which the starter
12 is supplied with electric power.
[0061] In the above embodiment, the engine 10 of the own vehicle 7
is jump-started using electric power supplied from the battery 31
of the rescue vehicle 30. However, the engine 10 of the own vehicle
7 may be jump-started using electric power supplied from a power
supply connectable to the battery 7 of the own vehicle 7, such as a
household emergency electric power supply.
[0062] The above explained preferred embodiments are exemplary of
the invention of the present application which is described solely
by the claims appended below. It should be understood that
modifications of the preferred embodiments may be made as would
occur to one of skill in the art.
* * * * *